Sensor networks (or sensor clouds) may comprise a plurality of wireless sensors that are tasked with performing various functions, e.g., security or monitoring functions (e.g., motion sensors, infrared sensors, light sensors, etc.), medical monitoring functions (e.g., temperature sensors, humidity sensors, heart rate sensors, oxygen sensors, gas sensors, etc.) and the like. Powering these sensors can be provided with efficient batteries, but these batteries must be replaced regularly to ensure that the sensors will operate properly. Failure to replace these batteries may create a security or medical issue.